Analysis of hydrogen isotope mixtures
AssigneeThe United States of America as represented by the United States Department of Energy
InventorEliel Villa-Aleman
Life of this patent
Estimating the term…
Abstract
An apparatus and method for determining the concentrations of hydrogen isotopes in a sample. Hydrogen in the sample is separated from other elements using a filter selectively permeable to hydrogen. Then the hydrogen is condensed onto a cold finger or cryopump. The cold finger is rotated as pulsed laser energy vaporizes a portion of the condensed hydrogen, forming a packet of molecular hydrogen. The desorbed hydrogen is ionized and admitted into a mass spectrometer for analysis.
Claims20
An apparatus for preparing a sample for analysis by a mass spectrometer, said analysis being made of the concentrations of any isotopes of an element in said sample, apparatus comprising:
- a first chamber having an interior;
- a second chamber in fluid communication with an ionization chamber of said mass spectrometer, said second chamber having an interior;
- a valve separating said first chamber from said second chamber, said valve having an open position and a closed position;
- means for preferentially admitting said element into said first chamber;
- means within said first chamber for collecting said element, said collecting means having a surface;
- and
- means proximate to said surface for vaporizing at least a portion of said element from said surface so that said portion can enter said second chamber, said vaporizing means producing a pulse of molecules having substantially uniform kinetic energies, said molecules of a lighter isotope of said element having a greater velocity than said molecules of a heavier isotope of said element so that, when said valve is in said open position, said molecules of said lighter isotope pass through said second chamber and reach said mass spectrometer before said molecules of said heavier isotope.
An apparatus for determining the concentrations of the isotopes of an element in a sample, said apparatus comprising:
- a first chamber having an interior;
- means for preferentially admitting said element into said first chamber;
- a second chamber in fluid communication with an ionization chamber of said mass spectrometer, said second chamber having an interior;
- a valve separating said first chamber from said second chamber, said valve having an open position and a closed position, said admitting means operable when said valve is in said closed position;
- means within said first chamber for collecting said element, said collecting means having a surface;
- means proximate to said surface for vaporizing at least a portion of said element from said surface, said vaporizing means operable when said valve is in said open position to produce a pulse of molecules having substantially uniform kinetic energies, said molecules of a lighter isotope of said element having a greater velocity than said molecules of a heavier isotope of said element so that said lighter molecules pass through said second chamber before said heavier molecules;
- means for ionizing said at least a portion, said molecules of said lighter isotope being ionized before said molecules of said heavier isotope;
- and
- means for separating isotopes in said at least a portion by mass.
A method for preparing a sample for analysis of the concentration of any isotopes of an element in said sample, said analysis being performed by a mass spectrometer, said method comprising the steps of:
- separating said element from said sample;
- collecting said element on a surface;
- vaporizing at least a portion of said collected element proximate to an ionization chamber of said mass spectrometer to produce a pulse containing molecules with substantially uniform kinetic energies, said molecules of a lighter isotope of said element having a greater velocity than said molecules of a heavier isotope of said element so that said molecules of said lighter isotope reach said ionization chamber before said molecules of said heavier isotope;
- when said molecules of an isotope of said element reach said ionization chamber, selectively ionizing said molecules of said isotope;
- repeating said ionizing step for each of said isotopes of said element;
- and
- passing said ionized molecules through a mass filter of said mass spectrometer.
Dependencies are inferred from the claim text.